sudanglo:

My favorite is typing "Mi parolas Esperanto" and asking Google to translate from Esperanto to English. So it translates it to "I speak English"

I reckon GT did good job there, showing some degree of machine intelligence. It sussed out that the omission of the accusative pointed to you being an English speaker (smiley emoticon).

When you type in Mi parolas Esperanton it seems to translate correctly into the half a dozen different languages I tried.

As to where the 'English' came from, it could just be some joker submitting a 'correction' to Google.

It is true that "Esperanto" gets translated as "English" about half the time, in a variety of different contexts, while "Esperanton" is always translated as "Esperanto" in all contexts. There was a thread about this some time back; I think it was entitled "Guglaj Strangaĵoj".